[PATCH AUTOSEL 4.14 121/186] driver core: platform: Prevent resouce overflow from causing infinite loops

[Sasha Levin]

From: Simon Schwartz <kern.simon@xxxxxxxxxxxxxxx>

[ Upstream commit 39cc539f90d035a293240c9443af50be55ee81b8 ]

num_resources in the platform_device struct is declared as a u32.  The
for loops that iterate over num_resources use an int as the counter,
which can cause infinite loops on architectures with smaller ints.
Change the loop counters to u32.

Signed-off-by: Simon Schwartz <kern.simon@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/2201ce63a2a171ffd2ed14e867875316efcf71db.camel@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/base/platform.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index f1105de0d9fed..e3d40c41c33b0 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -28,6 +28,7 @@
 #include <linux/limits.h>
 #include <linux/property.h>
 #include <linux/kmemleak.h>
+#include <linux/types.h>
 
 #include "base.h"
 #include "power/power.h"
@@ -68,7 +69,7 @@ void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
 struct resource *platform_get_resource(struct platform_device *dev,
 				       unsigned int type, unsigned int num)
 {
-	int i;
+	u32 i;
 
 	for (i = 0; i < dev->num_resources; i++) {
 		struct resource *r = &dev->resource[i];
@@ -163,7 +164,7 @@ struct resource *platform_get_resource_byname(struct platform_device *dev,
 					      unsigned int type,
 					      const char *name)
 {
-	int i;
+	u32 i;
 
 	for (i = 0; i < dev->num_resources; i++) {
 		struct resource *r = &dev->resource[i];
@@ -360,7 +361,8 @@ EXPORT_SYMBOL_GPL(platform_device_add_properties);
  */
 int platform_device_add(struct platform_device *pdev)
 {
-	int i, ret;
+	u32 i;
+	int ret;
 
 	if (!pdev)
 		return -EINVAL;
@@ -447,7 +449,7 @@ EXPORT_SYMBOL_GPL(platform_device_add);
  */
 void platform_device_del(struct platform_device *pdev)
 {
-	int i;
+	u32 i;
 
 	if (pdev) {
 		device_remove_properties(&pdev->dev);
-- 
2.20.1